What is the probability of spinning the spinner pictured and getting a prime number? Express your answer as a common fraction. [asy]
import olympiad; defaultpen(linewidth(0.8)); size(100); dotfactor=4;
draw(Circle((0,0),1));
string[] labels = {"3","6","1","4","5","2"};
for(int i = 0; i < 6; ++i){

label(labels[i],0.7*dir(60*i));

draw((0,0)--dir(60*i - 30));
}
draw((0,0)--0.7*dir(130),linewidth(2.0),EndArrow(size=6));
[/asy]
There are six possible numbers for the spinner to land on, three of which are prime (3, 2, and 5). Thus, the probability of spinning a prime number is $\boxed{\frac{1}{2}}$.